Unit for grading produce, such as fruits

ABSTRACT

The invention is embodied as a unit for grading produce and comprises a transporting device having parallel belts and receptacles which open downwardly and in which produce is arranged, and a weighing station comprising a weighing wheel driven in rotation by a gear motor and a section of which projects into the receptacles so as to carry the produce as it passes through the weighing station. The weighing wheel and the gear motor are supported by a device for weighing the produce. The unit also includes a grading station comprising several stations for ejecting the produce from the transporting device into a device for removing the produce as a function of the weight of the produce.

BACKGROUND OF THE INVENTION

The present invention relates to a unit or apparatus for gradingproduce, such as fruits.

Prior art grading units have consisted of bucket conveyors in whichfruits are placed, for example by means of automatic feed devices.

The buckets are connected to the conveyors in a manner such that theycan be weighed freely when they pass through a first part of the unitand pivot at the moment of discharging the fruit contained in the bucketfor grading thereof.

The weight of the fruit is obtained by automatically subtracting theweight of the bucket from the weight of the bucket and fruit as measuredtogether. The information obtained makes it possible to control a meansfor discharging the fruit such that the fruits can be classifiedaccording to weight.

However, these devices present certain drawbacks, the most important ofwhich lies in the fact that it is not possible to eliminate from themeasurement the effects of friction created because the bucket isweighed while being moved. Moreover, the vibrations generated by thismovement interfere with and thus reduce the accuracy of the weighingprocess.

The aim of the invention is therefore to solve these problems byproviding a grading unit which is simple, reliable, of a moderate costand accurate in measuring the weight of the produce such that gradingthereof is more accurate.

SUMMARY OF THE INVENTION

To this end, the subject of the invention is a unit for grading produce,such as fruits, characterized in that it comprises a transporting meanswhich includes parallel belts and receptacles which support the producebut open downwardly, a weighing station which includes carrying meansdriven by a gear motor and a section of which projects into thereceptacles so as to carry the produce when it passes through theweighing station device for weighing the produce which supports theweighing means and the gear motor, and a grading station comprising astation for ejecting the produce from the transporting means into ameans for removing the produce, as a function of the weight of theproduce.

Advantageously, the unit according to the invention also comprises feedmeans for feeding the produce and means for transferring the producefrom the feed means into the receptacles of the transporting means.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood with the aid of the followingdescription which is given solely by way of example and which is madewith reference to the appended drawings, wherein:

FIG. 1 is a schematic view of a grading unit according to the invention;

FIG. 2 represents a block diagram illustrating the operation of thegrading unit according to the invention;

FIG. 3 is a partial view of a feed means and of a transferring wheel ofthe invention;

FIG. 4 is a partial view of a transporting means and of a weighing wheelof the invention;

FIG. 5 illustrates the operation of an ejection means of the invention;

FIG. 6, 7, 8 and 9 illustrate different stages of a process of turning afruit in a unit according to the invention;

FIG. 10 represents a different embodiment of the transporting means andof a weighing wheel according to the invention;

FIG. 11 represents another embodiment of the weighing means according tothe invention; and

FIG. 12 represents another embodiment of transporting means according tothe invention.

DETAILED DESCRIPTION OF THE INVENTION

As may be seen in FIG. 1, a unit for grading produce according to theinvention comprises a transporting means having parallel belts andreceptacles with lower openings and in which the produce P is arranged.The unit according to the invention also comprises a weighing station 2comprising produce carrying means consisting, for example, of a weighingwheel 3 which is rotatably driven by a gear motor 4. A section 3a of theweighing wheel 3 projects into the receptacles of the transporting means1 so as to carry the produce as the produce passes through the weighingstation.

The wheel 3 and the gear motor 4 are supported by a weighing device 5for weighing the produce. The weighing device 5 is itself supported, forexample, by the frame of the unit. The weighing device 5 makes itpossible to determine the actual weight of the produce by subtractingthe weight measured when there is no produce on the wheel from theweight measured when there is produce on the wheel.

The unit according to the invention also comprises a grading station 6comprising several stations 7, 8 and 9 for ejecting the produce from thetransporting means 1 into the means 10, 11 and 12 for removing theproduce, respectively, as a function of the weight of the latter.

A feed means 13 for transporting the produce and transfer means 14 fortransferring the produce from the feed means 13 into the receptacles ofthe transporting means 1 are also provided in order to ensure automaticfeed.

As shown in FIG. 1, the transfer means 14 advantageously consists of atransferring wheel inserted between the transporting means 1 and thefeed means 13. This wheel will be described in more detail below.

Each ejection station comprises an ejection means (15, 16 and 17,respectively), which is driven by a control device connected to theweighing device 5 and to a detector 18 for detecting the position of theproduce with respect to the ejection stations. Moreover, a sensor 19also makes it possible to detect the presence of a fruit in the weighingstation in order to trigger measuring.

As is represented in FIG. 2, which illustrates the operation of a unitaccording to the invention, a control device 20 receives informationfrom the sensor 19 which indicates to it that a fruit is in a weighingposition. The control device 20 then triggers the weighing device 5 sothat it performs a measurement and the control device 20 receives fromthe weighing device 5 a signal corresponding to the weight of thewheel/gear motor/produce group, from which it determines the weight ofthe produce. This weight is then stored by the control device and, as afunction of the position of the produce as indicated by the detector 18,and the control device 20 activates one of the ejection means 15, 16, 17in dependence on the weight of the produce so as to eject the produceinto the removal means corresponding to the weight grade determined. Thevarious means described above present no particular problems inimplementation and will not be described in further detail.

The produce which is first arranged on the feed means 13 is transportedby the latter to the transferring wheel 14 which ensures proper transferand positioning of the produce one by one, into respective receptaclesof the transporting means 1, as illustrated in FIG. 1. The produce thenpasses through the weighing station 2 and is then ejected from thetransporting means towards the removal means 10, 11 and 12 which removesthem according to grade.

The speed of rotation of the transferring wheel 14 should be at leastequal to the speed of rotation of the feed means 13 and should be lessthan the speed of rotation of the transporting means 1 in order tocoordinate the various displacements of the produce on the varioustransporting and transferring means.

Moreover, the weighing wheel 3 and the transferring wheel 14 may alsohave flaps mounted on their periphery for receiving the produce so as tofacilitate movement of the produce by the wheels.

Both the weighing wheel and the transferring wheel preferably compriseat least two discs of the same diameter separated by a distance which isless than the size of the produce so as to ensure proper support for theproduce.

As may be seen in FIG. 3 and 4, the transferring wheel 14 and theweighing wheel 3 can each comprise a set of three discs 21, 22, 23 and24, 25, 26, respectively. The two outer discs of each set (i.e. discs21, 23 and 24, 26, respectively) are of equal diameter. The center discof each set (i.e. discs 22 and 25, respectively) have a diameter whichis less than the diameter of the two outer discs so that straight linespassing through the upper most points of each of the outer discs and thecenter discs have an angle α of between 100° and 180° formedtherebetween. This angle provides good support and lateral guiding forthe produce.

Moreover, each of the feed means 13 and the transporting means 1 canalso comprise at least two elongated elements (27, 28 and 29, 30,respectively) for transporting and for laterally guiding the produce.These two elongated transporting elements are arranged in parallel andare separated from one another by a distance which is less than the sizeof the produce so as to form a support and guiding chute for the latter.The transporting elements 27, 28 and 29, 30 form, as shown in FIG. 1,loops which are trained around two guiding members 31, 32 for the feedmeans 13, and are trained around four guiding members 33, 34, 35, 36 forthe transporting means 1.

Advantageously, these transporting elements consist of chains with linksupon which support members 37, 38 and 39, 40, respectively, are fixed.The produce is supported on the upper faces of the support members 37,38 and 39, 40 (see especially FIG. 4).

According to one embodiment, the upper faces of the support members 37,38 and 39, 40 form an angle β therebetween of at least 100°. Accordingto one particular embodiment, these upper faces are arranged in one andthe same plane (i.e. β=180°).

As shown in FIG. 4, the receptacles of the transporting means 1 can bedelimited by parts 41, 42 projecting from the transporting elements 29and 30.

Each of the ejection means, for example the ejection means 15 (FIG. 5),comprises an actuator 43 arranged below the transporting means 1. Theactuator 43 included an exit shaft 44 which comprises at least oneejection finger and, in the example illustrated, two ejection fingers45, 46 offset angularly so as to eject the produce P in a specificdirection onto the removal means 10, for example, following a commandfrom the corresponding actuator.

The produce P shown in the figures may consist, for example, of orangesor apples of an approximately spherical shape. However, it should benoted that the unit according to the invention is also suitable forweighing and grading produce, such as pears or avocados, which have afirst part whose shape corresponds approximately to a section of asphere and a second part which extends from the first part in anapproximately frustoconical shape, and in which the first part has amass greater than the second. In this case, and as is represented inFIGS. 6 to 9, the feed means 13 and the transferring wheel 14 form adevice for positioning this produce in a specific direction. In fact,the intersection between the feed means 13 and the transferring wheel 14forms a space, with a flared V-shaped cross section, for turning producewhich arrives with its approximately frustoconical smaller mass in frontby way of relative movement between the two branches of the V formed bythe opposing sections of the feed means 13 and the transferring wheel14. As has been described above, the feed means and the transferringmeans comprise means for laterally guiding the produce so that its axisof displacement (feed direction) of the feed means and the transferringmeans, such that produce which arrives with its section of approximatelyfrustoconical shape at the front can be set upright and then turned andfinally transferred by the transferring wheel to the transporting means1.

It goes without saying that the wheel for transferring the produce mayconsist of any transferring means which defines, with the feed means 13,a space having a flared V-shaped cross section for turning the produce.

As shown in FIG. 10, which represents a different embodiment of the feedmeans and/or of the transporting means, the transporting means canconsist of three transporting elements 47, 48 and 49 consisting, forexample, of cylindrical belts of a deformable material trained aroundthe guiding means mentioned above.

These guiding means, for example 31, comprise three guiding grooves 50,51, 52, one 51 of which is arranged in a portion 31a of the guidingmeans 31 which has a reduced cross section for guiding the centertransporting element 48 arranged between the two outer transportingelements 47 and 49, so that planes tangent to the free surfaces of thebelts form an angle γ of at least 100° between them.

In this embodiment, the receptacles of the transporting means can, forexample, consist of pieces 53 in the shape of a bridge extending betweenthe two outer transporting elements 47 and 49.

The weighing wheel 54 and/or the transferring wheel can comprise fourdiscs 55, 56, 57, 58 to ensure proper guiding of the produce as it istransferred and/or as it is weighed.

As shown in FIG. 11, which represents yet another embodiment of theweighing means according to the invention, the weighing station 2comprises a carrying means which, for example, includes the weighingwheel 3 driven in rotation by the gear motor 4, and the weighing device5 for supporting the weighing wheel 3 and the motor 4 and for weighingthe produce, as well as means 60 for gripping the produce when it passesinto the weighing station.

Advantageously, the gripping means 60 comprises an auxiliary wheel 61consisting of a deformable material such as, for example, rubber. Theauxiliary wheel 61 is arranged above the weighing wheel 3 and has anaxis which is parallel to the axis of the weighing wheel 3, so as toprovide a deformable weighing passage between these two wheels of a sizewhich is less than the size of the produce.

The auxiliary wheel 61 is driven at the same speed but in the oppositedirection of rotation with respect to the weighing wheel 3. Theauxiliary wheel 61 is driven by the gear motor 4 via a system of pulleysand a belt. This arrangement provides an advantageous gripping of theproduce as it passes into and through the weighing station.

As also shown in FIG. 11, the weighing station is arranged such that theproduce is gripped between the weighing wheel 3 and the auxiliary wheel61 which deforms in an elastic manner so as to avoid any damage to theproduce as the produce passes into and through the weighing station.

It should be noted that the weighing wheel 3 and the auxiliary wheel 61preferably have the same initial diameter. This makes it possible toprovide proper gripping of the produce when the produce arrives in theweighing station so as to avoid round produce, such as oranges, fromidly spinning about their own axes when they encounter the weighingwheel 3.

It should also be noted that the auxiliary wheel 61 is carried by themeasuring device 5 so as to avoid interfering with the measurement.

Moreover, this device also results in increased accuracy of measurementsince the gripping means holds the produce as it is being weighed.

Finally, and as shown in FIG. 12, the transporting means can alsoconsist of parallel belts 62 and 63 on which support studs, for example64, 65, 66 and 67, 68, 69, respectively, are fixed. These support studsform, in groups of four, means for supporting produce (represented byphantom lines in FIG. 12).

I claim:
 1. An apparatus for grading produce, comprising:transportingmeans for transporting the produce, said transporting means comprisingtwo parallel elements and produce receptacles operatively connected tosaid parallel elements for receiving produce, each of said receptacleshaving a lower opening; a weighing station comprising a produce carryingmeans for carrying and supporting the produce as it is being weighed, amotor operatively connected to said produce carrying means to drive saidproduce carrying means and a weighing means for supporting said producecarrying means and said motor and for weighing said produce, saidproduce carrying means including a section which projects through saidlower opening in each of said receptacles as they pass thereover so asto carry the produce as it passes through the weighing station; meansfor removing the produce as a function of the weight of the produce; anda grading station comprising a plurality of ejection stations, each ofwhich includes a means for ejecting the produce from said transportingmeans into said removing means.
 2. An apparatus as recited in claim 1,further comprisinga feed means for feeding the produce to saidtransporting means; and a transferring means for transferring theproduce from said feed means into said receptacles of said transportingmeans.
 3. An apparatus as recited in claim 2, whereinsaid transferringmeans comprises a rotatable transferring wheel mounted between said feedmeans and said transporting means.
 4. An apparatus as recited in claim3, whereinsaid transferring wheel has flaps mounted about its peripheryto aid in transferring the produce.
 5. An apparatus as recited in claim3, whereinsaid transferring wheel comprises at least two substantiallyparallel discs separated by a distance which is less than a diameter ofthe produce.
 6. An apparatus as recited in claim 5, whereinsaid at leasttwo substantially parallel discs comprises three substantially paralleldiscs, a center disc of said three discs having a smaller diameter thanouter discs of said three discs such that a straight line passingthrough an uppermost point on the periphery of said center disc and anupper most point on the periphery of one of said outer discs forms anangle of between 100° and 180° with a straight line passing through saiduppermost point on the periphery of said center disc and an uppermostpoint on the periphery of the other of said outer discs.
 7. An apparatusas recited in claim 3, whereinmeans for causing said transferring meansto move the produce at a speed at which said feed means moves theproduce and less than a speed at which said transporting means moves theproduce.
 8. An apparatus as recited in claim 2, further comprisingatleast two guiding members; and wherein said feed means comprises twosubstantially parallel endless elements trained about said at least twoguiding members, said two endless elements being separated by a distancewhich is less than a diameter of the produce such that they form asupport and guiding chute for the produce.
 9. An apparatus as recited inclaim 8, whereineach of said two elongated elements comprises an endlesschain formed of links; and support members are fixed to said links andare adapted to support produce on upper faces thereof.
 10. An apparatusas recited in claim 9, whereinsaid support members are mounted such thatupper faces of said support members on opposing ones of said endlesschains are inclined toward each other such that a relative angletherebetween is at least 100°.
 11. An apparatus as recited in claim 9,whereinsaid upper faces of said support members are arranged in the sameplane.
 12. An apparatus as recited in claim 8, whereineach of said atleast two guiding members has three annular grooves therein, a centergroove of said three annular grooves being formed in a small diameterportion of each of said at least two guiding members, and two outergrooves of said three annular grooves being formed in two largerdiameter portions of each of said at least two guiding members relativeto said small diameter portion; and said feed means comprises a thirdendless element substantially parallel with and mounted between said twoendless elements, each of said three endless elements being formed as adeformable belt and disposed in a respective one of said three annulargrooves of each of said guiding members; such that a plane which istangential to the center one of said endless belts and one of the outerones of said endless belts is angled by at least 100° with respect to aplane which is tangential to said center one of said endless belts andthe other of said outer ones of said endless belts.
 13. An apparatus asrecited in claim 1, whereinsaid carrying means comprises a weighingwheel supported by said weighing means and rotatably driven by saidmotor.
 14. An apparatus as recited in claim 13, whereinsaid carryingmeans further comprises flaps mounted about a periphery of said weighingwheel to aid in carrying the produce.
 15. An apparatus as recited inclaim 13, whereinsaid weighing wheel comprises at least twosubstantially parallel discs separated by a distance which is less thana diameter of the produce.
 16. An apparatus as recited in claim 15,whereinsaid at least two substantially parallel discs comprise threesubstantially parallel discs, a center disc of said three discs having asmaller diameter than outer discs of said three discs such that astraight line passing through an uppermost point on the periphery ofsaid center disc and an uppermost point on the periphery of one of saidouter discs forms an angle of between 100° and 180° with a straight linepassing through said uppermost point on the periphery of said centerdisc and an uppermost point on the periphery of the other of said outerdiscs.
 17. An apparatus as recited in claim 13, whereinsaid weighingstation further comprises means for gripping the produce as it passesthrough said weighing station.
 18. An apparatus as recited in claim 17,whereinsaid gripping means comprises an auxiliary wheel formed ofdeformable material and mounted for rotation about an axis parallel to arotational axis of said weighing wheel, said auxiliary wheel beingseparated from said weighing wheel by a weighing passage which issmaller than a diameter of the produce, and a means for connecting saidauxiliary wheel to said motor such that said auxiliary wheel is drivenin a direction opposite the direction in which said weighing wheel isdriven.
 19. An apparatus as recited in claim 1, further comprisingatleast two guiding members; and wherein said two parallel elements ofsaid transporting means comprise two substantially parallel endlesselements trained about said at least two guiding members, said twoendless elements being separated by a distance which is less than adiameter of the produce such that said two endless elements form asupport and guiding chute for the produce.
 20. An apparatus as recitedin claim 19, whereineach of said two elongated elements comprises anendless chain formed of links; and support members are fixed to saidlinks and are adapted to support produce on upper faces thereof.
 21. Anapparatus as recited in claim 20, whereinsaid support members aremounted such that upper faces of said support members on opposing onesof said endless chains are inclined toward each other such that arelative angle therebetween is at least 100°.
 22. An apparatus asrecited in claim 20, whereinsaid upper faces of said support members arearranged in the same plane.
 23. An apparatus as recited in claim 19,whereineach of said at least two guiding members has three annulargrooves therein, a center groove of said three annular grooves beingformed in a small diameter portion of each of said at least two guidingmembers, and two outer grooves of said three annular grooves beingformed in two larger diameter portions of each of said at least twoguiding members relative to said small diameter portion; and saidtransporting means further comprising a third endless elementsubstantially parallel with and mounted between said two endlesselements, each of said three endless elements being formed as adeformable belt and disposed in a respective one of said three annulargrooves of each of said guiding members; such that a plane which istangential to the center one of said endless belts and one of the outerones of said endless belts is angled by at least 100° with respect to aplane which is tangential to said center one of said endless belts andthe other of said outer ones of said endless belts.
 24. An apparatus asrecited in claim 19, whereinsaid receptacles of said transporting meansare delimited by parts projecting upwardly from said endless elements.25. An apparatus as recited in claim 19, whereinsaid receptacles of saidtransporting means are delimited by bridge shaped elements extendingbetween said endless elements.
 26. An apparatus as recited in claim 1,further comprisingcontrol means for controlling each of said ejectingmeans; detector means for detecting positions of the produce relative toeach of said ejecting means and for providing a position signal to saidcontrol means; and wherein said weighing means is operable to provide aweight signal to said control means.
 27. An apparatus as recited inclaim 26, whereineach of said ejecting means comprises an actuator meansfor causing said ejecting means to eject the produce in a desireddirection onto said removal means, said actuator means being mountedbelow said transporting means and including an exit shaft and at leastone ejection finger extending from said exit shaft.
 28. An apparatus asrecited in claim 1, whereineach of said parallel elements of saidtransporting means comprises an endless belt having a plurality of studsmounted thereon to support the produce.